War declared … Richard, Duke of York (left) plucks a white rose while the Duke of Somerset, Henry VI's principal supporter, plucks a red one, at the start of the conflict that would be known as the Wars of the Roses. Photograph: Popperfoto

The Grand Old Duke of York had ten thousand men, but why did he march them up to the top of the hill and then march them down again?

The nursery rhyme might go back to the Wars of the Roses between the Houses of York and Lancaster, when Richard, Duke of York, tried to claim the throne from Henry VI. The Lancastrians came after him with a great army and in December 1460 the Duke of York and his troops headed for their stronghold at Sandal Castle, near Wakefield, but they were dogged by rain, flooding, waterlogged roads and broken bridges along the way.

Eventually, on 21 December, they reached Sandal Castle, built on a commanding small hill overlooking open ground. But the pursuing Lancastrians soon caught up and lay in wait. Hopelessly outnumbered, the Yorkists had to wait for reinforcements.

No one is sure why, but on 30 December the Duke of York led his troops out of Sandal Castle, down the hill and on to the open, exposed ground below. There they were ambushed by the Lancastrian army and routed, and both the Duke of York and his son killed.

No one is sure why Richard made such a reckless move, but that winter was bitterly cold as well as wet, and despite their strong defensive position at Sandal Castle, the Yorkist army were desperate for supplies before reinforcements could arrive. And so the Grand Old Duke of York came a cropper.